Catheter having tapered guide surface

Abstract

Medical devices and methods for making and using medical devices are disclosed. An example catheter is disclosed. The catheter comprises a catheter body having a catheter lumen and a high pressure tube disposed within the catheter lumen. The high pressure tube has a substantially circular cross section. The catheter also includes a fluid jet loop coupled to the high pressure tube at a transition section. The transition section has a circular cross section and a non-circular cross section. The fluid jet loop includes fluid jet orifices along a tapered loop guide surface. The catheter also includes a distal guide. The intermediate guide surface of the catheter lumen flushly engages with a leading edge of the tapered loop guide surface and the distal guide is configured to guide the instrument over the intermediate guide surface, the tapered loop guide surface and through the fluid jet loop.

What is claimed is: 
     
       1. A catheter comprising:
 a catheter body with a catheter lumen extending from a proximal catheter portion to a distal catheter portion; 
 a high pressure tube disposed within the catheter lumen and extending longitudinally from the proximal catheter portion to the distal catheter portion, wherein the high pressure tube has a substantially circular cross section; 
 a fluid jet loop coupled to the high pressure tube at a transition section, the transition section having a circular cross section and a non-circular cross section, wherein the non-circular cross sectional shape defines a tapered loop guide surface and a loop perimeter surface, wherein the fluid jet loop extends circumferentially around a fluid jet loop lumen, the fluid jet loop includes fluid jet orifices along the tapered loop guide surface, and the tapered loop guide surface tapers from a fluid jet loop outer perimeter toward a fluid jet loop inner perimeter and the fluid jet loop lumen; 
 a distal guide including the tapered loop guide surface and an intermediate guide surface of the catheter lumen flushly engaged with a leading edge of the tapered loop guide surface, wherein the distal guide is configured to guide the instrument over the intermediate guide surface, the tapered loop guide surface and through the fluid jet loop. 
 
     
     
       2. The catheter of  claim 1 , wherein the tapered loop guide surface tapers inwardly away from the intermediate guide surface toward the fluid jet loop lumen. 
     
     
       3. The catheter of  claim 1 , wherein the fluid jet loop includes a distal guide surface, and the distal guide surface tapers inwardly from a distal edge flushly engaged with the intermediate guide surface toward the fluid jet loop lumen. 
     
     
       4. The catheter of  claim 1 , wherein the intermediate guide surface includes the catheter body interior wall. 
     
     
       5. The catheter of  claim 1 , further comprising a support ring coupled with the fluid jet loop, and the support ring includes a support ring lumen in communication with the fluid jet loop lumen. 
     
     
       6. The catheter of  claim 1 , wherein the catheter body includes one or more inflow and outflow orifices extending from the catheter lumen to a catheter exterior near the catheter distal portion, and the one or more inflow orifices are positioned between the one or more outflow orifices and the fluid jet loop. 
     
     
       7. The catheter of  claim 6 , wherein one or more of the inflow and outflow orifices are configured to receive a fluid flow over the catheter exterior of around 1 to 500 meters per second, and the fluid flow at least extends from one or more of the outflow orifices to one or more of the inflow orifices. 
     
     
       8. The catheter of  claim 7 , wherein the high pressure tube may extend over the outflow and inflow orifices. 
     
     
       9. The catheter of  claim 1 , comprising a support ring extending around the catheter body interior wall. 
     
     
       10. The catheter of  claim 9 , wherein the support ring engages an annular shoulder formed in the catheter body interior wall. 
     
     
       11. The catheter of  claim 10 , wherein the support ring includes an annular groove sized and shaped to receive the annular shoulder. 
     
     
       12. The catheter of  claim 9 , wherein the support ring includes a support ring lumen extending through the support ring and wherein the support ring lumen is circumscribed by a distal tapered surface. 
     
     
       13. The catheter of  claim 12 , wherein the annular groove is positioned between the fluid jet loop and the distal tapered surface. 
     
     
       14. The catheter of  claim 12 , wherein the distal tapered surface facilitates front loading of an instrument through the catheter body. 
     
     
       15. A catheter comprising:
 an elongate tubular member having an outer wall, an inner wall, and an inner lumen, wherein the inner wall extends from a proximal catheter portion to a distal catheter portion; 
 a high pressure tube disposed within the inner lumen and extending longitudinally from the proximal catheter portion to the distal catheter portion, wherein the high pressure tube has a substantially circular cross section; 
 a fluid jet loop coupled to the high pressure tube, the fluid jet loop having a non-circular cross section, wherein the non-circular cross section defines a perimeter loop surface, a taper loop surface and a distal loop surface, wherein the perimeter loop surface is substantially parallel to the inner wall of the elongate tubular member, and wherein the distal loop surface is substantially orthogonal to the inner wall of the elongate tubular member; 
 a support ring positioned distal the fluid jet loop, the support ring having a support ring mating surface, wherein the distal loop surface extends along the distal support ring mating surface.